Method of use for percutaneous material removal device and tip

ABSTRACT

A method of removing material from a body lumen in a patient in need of such removal, comprising advancing a catheter-mounted device having a distal material removal tip including a hollow housing and a member rotatable therewithin, rotating the rotatable member, drawing said material into said housing, shearing said material in said housing between relatively rotating shearing members to reduce the clogging propensity of said material, and removing said sheared material from within said housing as said material removal tip is advanced through said vessel. In another embodiment, the rotatable member of the invention includes grinding means for grinding the material prior to the contact of the material with the shearing member. An article of manufacture that includes packaging material and instructions in the method of the invention contained within the packaging material is also taught.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This is a continuation-in-part of application Ser. No.09/303,038, filed Apr. 30, 1999, which has been allowed for Issuance asa U.S. Letters Patent, and for which the issue fee has been paid, theentire disclosure of which is hereby expressly incorporated herein byreference. Likewise, co-pending C-I-P, U.S. Ser. No. 09/766,150 filed onJan. 18, 2001, based upon the same parent, in the name of the sameinventors, and assigned to instant assignee is expressly incorporatedherein by reference, in its entirety.

BACKGROUND OF THE INVENTION

[0002] The present invention is related to methods and apparatus forclearing blocked natural and synthetic vessels, and more specifically,to methods and apparatus for percutaneously clearing material fromvessels with a rotating device and suction, without luminal damage.

[0003] A variety of techniques and instruments have been developed foruse in the removal or repair of obstructive material in vessels andother body passageways. Such material may include atheromas, thrombi, oremboli. An atheroma is a mass of plaque of degenerated, thickenedarterial intima occurring in atherosclerosis. A thrombus is anaggregation of blood factors, primarily platelets and fibrin withentrapment of cellular elements, frequently causing vascular obstructionat the point of its formation. An embolus is a clot or other plugbrought by the blood from another vessel and forced into a smaller one,thus obstructing the circulation, generally.

[0004] Many catheter-mounted devices are presently available forremoving material from vessels. Some of these devices include rotatableabrasive members on the distal tip of a flexible catheter, which tend toremove hardened atherosclerotic materials without damaging the normalelastic soft tissue of the vessel wall. However, long standing needsremain.

[0005] Another material removal device is seen in the U.S. Pat. No.5,423,799 to Shiu, and includes a tubular housing mounted on the distalend of a catheter within which a helical screw member rotates. The screwincludes a sharp edge which, in cooperation with housing, cuts thetissue and draws it into the housing for later removal. Artisanrecognize maceration issues with the devices and methods practiced underthis patent.

[0006] Despite advances made in catheter-mounted material removaldevices, many of them remain limited in their operational capacity, andtend to clog up fairly quickly. This necessitates the surgeon advancingvery slowly through the material blockage, and greatly increases thelength of surgery. In the worst-case, the device becomes irreversiblyclogged, and must be removed and another device procured andsubstituted. Therefore, there remains a need for a more efficientcatheter-mounted material removal device that can rapidly cut through amass of blocking material without clogging. Likewise, aninterventionist—friendly method and apparatus method remain outstanding.

BRIEF SUMMARY OF THE INVENTION

[0007] In one embodiment, the present invention provides a device forremoving material from a body lumen including an elongate, flexible tubehaving distal and proximal ends and a passageway there through. Thedevice has a material removal tip on the distal end including an outerhousing rotationally fixed with respect to the tube and a rotatingmember within the housing. The housing includes a lumen extending from adistal open mouth to the tube passageway. The rotating member includesdistal and proximal ends, a central body, and a plurality ofcircumferentially spaced flanges extending radially outward from thebody. At least one shearing member is formed within the lumen of thehousing and axially adjacent to the flange to cooperate with the flangeand shear material received in the housing mouth. The shearing membermay be located distally or proximal with respect to the flanges, orshearing members on both sides of the flanges may be provided. Thehousing desirably includes proximal and distal sections, each includinglumens, and an annular groove larger than either the distal or proximalsections and formed therebetween for axially restraining the flanges onthe rotating member. The shearing member is preferably located adjacentto the groove. The housing may be formed in one piece or two separatepieces.

[0008] In a preferred embodiment, the rotating member has a central bodyand a helical screw thread thereon and is driven by a drive shaft thatextends through a catheter attached to the housing. The shearing memberhas a radial dimension that brings it into close proximity with anassociated rotating member. That is, a distal shearing member is sizedto come into close proximity with the central body of the rotatingmember, while a proximal shearing member is sized to come into closeproximity with a drive shaft.

[0009] In another aspect, the present invention provides a materialremoval tip for use in a catheter-mounted material removal device,comprising a rotatable member having an outwardly projecting shearingmember, and a generally tubular housing sized to receive the rotatablemember. The housing includes a stationary shearing member locatedaxially adjacent to the rotating shearing member. The stationary androtating shearing members cooperate to chop material received within thehousing, reducing the clogging propensity of the material. There ispreferably a plurality of rotating shearing members axially restrainedwithin a groove formed on the inner surface of the housing. Thestationary shearing member is desirably located adjacent to groove,either proximally, distally, or both in the case of two stationaryshearing members.

[0010] The present invention further provides a method of materialremoval, including advancing through a body lumen a catheter-mountedmaterial removal device having distal material removal tip including ahollow housing and a rotatable member therewithin. The rotatable memberis rotated to engage the material, which is then sheared in the housingbetween relatively rotating shearing members to reduce the cloggingpropensity of material. Subsequently, the sheared material is removedfrom within the housing as the device is further advanced through thebody lumen.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a schematic view of a hand-held material removal systemwithin which the material removal device of the present invention isincorporated;

[0012]FIG. 2a is a longitudinal sectional view through one embodiment ofa material removal tip of the present invention having a two-piecehousing;

[0013]FIG. 2b is an end elevational view of the material removal tiphaving a two-piece housing, taken along line 2 b-2 b of FIG. 2a;

[0014]FIG. 2c is a sectional view of a stationary shearing member of theproximal housing section in operation, taken along line 2 c-2 c of FIG.2b;

[0015]FIG. 2d is a sectional view of a stationary shearing member of thedistal housing section in operation, taken along line 2 d-2 d of FIG.2b;

[0016]FIG. 3a is a longitudinal sectional view through a proximalhousing section of the material removal tip of FIG. 2a;

[0017]FIG. 3b is an end elevational view of the proximal housingsection, taken along line 3 b-3 b of FIG. 3a;

[0018]FIG. 4a is a longitudinal sectional view through a distal housingsection of the material removal tip of FIG. 2a;

[0019]FIG. 4b is an end elevational view of the distal housing section,taken along line 4 b-4 b of FIG. 4a;

[0020]FIG. 5a is a longitudinal sectional view through a secondembodiment of a material removal tip of the present invention having aone-piece housing;

[0021]FIG. 5b is an end elevational view of the material removal tiphaving a one-piece housing, taken along line 5 b-5 b of FIG. 5a;

[0022]FIG. 6a is a longitudinal sectional view through the one-piecehousing of the material removal tip of FIG. 5a;

[0023]FIG. 6b is an end elevational view of the one-piece housing, takenalong line 6 b-6 b of FIG. 6a;

[0024]FIG. 7a is a longitudinal sectional view through an alternativeone-piece housing in accordance with the present invention;

[0025]FIG. 7b is an end elevational view of the alternative one-piecehousing, taken along line 7 b-7 b of FIG. 7a;

[0026]FIG. 8a is a longitudinal sectional view through yet a stillfurther embodiment of a material removal tip of the present inventionwherein the rotatable member includes a grinding means, according to theinstant teachings, and,

[0027]FIG. 8b is an end elevational view of still yet another grindingmeans of the present invention.

DETAILED DESCRIPTION

[0028] The present inventors have discovered an improved method forpercutaneous material to be made into small pieces and withdrawn fromaffected luminal spaces. Likewise, the instant teachings arephysician/interventionist—friendly and useful.

[0029] With reference to FIG. 1, a material removal system 10 suitablefor use with the present invention comprises an elongate flexible tube12 having a proximal end 14 and a distal end 16. A hand-held control 18attached to the proximal end 14 of the tube 12 permits manipulation ofthe system. The control 18 carries electronic circuitry, controls, andindicators. A source of vacuum 20 communicates with the hand-heldcontrol 18 which in turn includes passages for creating a negativepressure in the interior of the tube 12. In addition, a drive motor (notshown) is mounted within the hand-held control 18 for supplyingrotational motion to a flexible drive shaft 22 (FIG. 2a) extendingthrough the elongated tube 12. A tubular removal passageway 24 is thusdefined in the space outside of the drive shaft 22 and within theflexible tube 12. The drive shaft 22 is preferably hollow to permitpassage therethrough of a guidewire 28.

[0030] The present invention provides an improved distal materialremoval tip 30, which is shown in detail in FIGS. 2, 3 and 4. Theremoval tip 30 comprises an outer housing 32 and a member 34 receivedtherewithin for rotation about an axis 37. The outer housing 32 has asubstantially hollow tubular shape and comprises a distal section 36 anda proximal section 38, through which a continuous lumen 40 extends. Thelumen 40 is defined by a distal lumen 42 within the distal section 36; aproximal lumen 44 within the proximal section 38, and an annular groove46 located intermediate the distal and proximal sections, all beingaxially aligned. In the illustrated embodiment, the groove 46 has alarger diameter than the distal lumen 42, which in turn has a largerdiameter than the proximal lumen 44. The rotatable member 34 is receivedwithin the distal housing section 36, with a portion within the groove46, as will be described below.

[0031] The aforementioned flexible tube 12 is seen in phantom coaxiallyreceived over a tubular body 50 on the proximal housing section 38.Likewise, the drive shaft 22 is seen in phantom extending through theflexible tube 12 and through the proximal lumen 44 into engagement withthe rotatable member 34. In this manner, the drive shaft 22 and member34 rotate together within the housing 32. A number of different driveshaft configurations may be utilized with the present invention, none ofwhich should be construed as limiting. Both the elongated tube 12 anddrive shaft 22 are seen in phantom in FIG. 2a, and thus are not seen inthe end view of FIG. 2b.

[0032] As mentioned, the rotatable member 34 is partly received withinthe groove 46. More particular, the rotatable member 34 comprises agenerally cylindrical or tubular body 56 from which a continuous helicalscrew thread 58 radially outwardly extends. The screw thread 58 beginsat a distal face 60 of the member 34 and continues around the body 56for approximately two-thirds of its length. A plurality of cantileveredfingers 62 defined by longitudinal slots 64 are provided on the proximalend of the member 34. Each of the fingers 62 carries an outwardlyextending cutter or flange 66, each of which in axial projection has agenerally truncated triangular shape as seen in FIG. 2b. There arepreferably three such flanges 66 evenly circumferentially spaced andforming somewhat of a propeller configuration about the rotatable member34. The flanges 66 terminate in outer tips that together define a circlehaving a diameter greater than the diameter of the distal lumen 42, butless than the diameter of the groove 46.

[0033] With reference to FIGS. 3a and 3 b, the proximal housing section38 includes the tubular body 50 terminating on its distal end in aradially outwardly extending annular shoulder 70 having a diameter thatis reduced at a step 72 to a cylindrical land 74 ending at a distal face76.

[0034] And seen in FIGS. 4a and 4 b, the distal housing section 36 alsoincludes a tubular body 80 extending from a distal mouth 82 to aproximal end 84. The lumen 42 extends proximally from the mouth 82 untila step 86 increases the diameter to that of a stepped bore 88.

[0035] The land 74 of the proximal housing section 38 has a diameterthat is approximately equal to the diameter of the bore 88.Consequently, the distal end of the proximal housing section 38 isclosely received within the bore 88 until the proximal end 84 contactsthe step 72. By cooperation between the distal and proximal sections 36,38, the groove 46 is defined on its outer side by the bore 88, and onrespective axial sides by the distal face 76 of the proximal housingsection 38 and the step 86 of the distal housing section 36. Therotatable member 34 is captured in the location of FIG. 2a bycooperation between the outwardly projecting flanges 66 and the groove46. The cantilevered fingers 62 enable inward deflection of the flanges66 so that they can pass through the distal lumen 42 of the housing 32and snap outward into the groove 46. The spacing between the flanges 66and the groove 46 are slightly exaggerated in the drawings, and in aworking model of the device the axial dimension of the flanges 66 willbe slightly smaller than the spacing between the step 86 and the distalface 76. In this manner, the flanges 66 are constrained in the groove 46from even slight axial movement.

[0036] The present invention provides at least one shearing member thatis axially adjacent the flanges 66. In the embodiment of FIGS. 24, thereare two such shearing members, a distal member 100 and a proximal member102. The distal shearing member 100 projects radially inwardly withrespect to the distal lumen 42 of the distal housing section 36.Likewise, proximal shearing member 102 projects radially inwardly withrespect to the proximal lumen 44 of the proximal housing section 38. Asseen best in FIG. 4a, the distal shearing member 100 has a proximal face104 which is co-extensive with the step 86. The proximal face 104 isthus positioned on the edge of the groove 46 closely adjacent to therotating flanges 66. In like manner, as seen in FIG. 3a, the proximalshearing member 102 has a distal face 106 which is co-extensive with thedistal face 76 of the proximal housing section 38. The distal face 106is thus positioned on the edge of the groove 46 closely adjacent to therotating flanges 66.

[0037] With reference to the detailed views of FIGS. 3-4, the shearingmembers 100, 102 in a preferred embodiment resemble teeth. Morespecifically, the distal shearing member 100 includes an arcuate innerface 110 having a relatively small included angle 112 and transitionsurfaces 114 on either side joining the inner face to the distal lumen42. The proximal shearing member 102 includes an arcuate inner face 120having an included angle 122 and transition surfaces 124 on either sidejoining the inner face to the proximal lumen 44. The small includedangles 112, 122 and generally radially oriented transition surfaces 114,124 define shearing members 100, 102 of relatively small angular size.The angular size must of course be sufficient to provide shearingstrength in operation, as will be described, but should be kept to aminimum to reduce the obstruction to flow of material through thehousing 32.

[0038] As seen in FIG. 2a, each of the shearing members 100, 1-02 has aradial dimension sufficient to bring its respective inner face 110, 120into close proximity with an adjacent rotating element. That is, theinner face 110 of the distal shearing member 100 is spaced across a gap130 from the body 56 of the rotatable member 34. Similarly, the innerface 120 of the proximal shearing member 102 is spaced across a gap 132from the drive shaft 22. The gaps 130 and 132 are preferably minimizedwithout risking contact between the respective rotating element andshearing member. Illustrative numerical ranges are presented herewith,and will be known by artisans to be exemplary and not limiting. Morespecifically, the gaps 130 and 132 are each desirably greater than zerobut less than 0.254 mm (0.01 inches). More preferably, the gaps 130 and132 are each less than 0.0254 mm (0.001 inches), and most preferably thegaps are each less than 0.0127 mm (0.0005 inches).

[0039] Each of the inner faces 110, 120 of the shearing members 100, 102preferably has an arcuate surface concentric with the axis of rotationof the adjacent rotating element. In addition, the inner faces 110, 120preferably have a radius of curvature that corresponds to the adjacentrotating elements. Namely, the distal shearing member 100 has an innerface 110 that is the same radius of curvature as the body 56 of therotatable member 34, and the inner face 120 of the proximal shearingmember 102 has a curvature that is the same as the external diameter ofthe drive shaft 22. In one embodiment, merely offered for considerationas an illustration of the teachings of the present invention, the radiusof curvature of the inner face 110 is about 1.194 mm (0.047 inches), andthe radius of curvature of the inner face 120 is about 0.991 mm (0.039inches).

[0040] As illustrated in FIG. 2b, the distal shearing member 100 isoriented 180 degrees about the housing 32 with respect to the proximalshearing member 102. In practice, the relative orientation of theshearing members 100, 102 about the housing 32 is not consideredespecially significant. Therefore, the shearing members 100, 102 may beaxially aligned, or offset with respect to one another around thecircumference of the housing 32 at any relative orientation.

[0041] The axial and circumferential dimensions of each of the shearingmembers 100, 102 must be sufficient to provide adequate strength withoutinordinately blocking the lumen 40 through the housing 32. In oneembodiment, for example, it has been discovered that the distal lumen 42has a diameter of approximately 1.75 mm (0.069 inches), and the distalshearing member 100 has an axial dimension of approximately 0.279 mm(0.011 inches) and an included angle of approximately 25 degrees. In thesame embodiment, the proximal lumen 44 has a diameter of approximately1.42 mm (0.056 inches), and the proximal shearing member 102 has anaxial dimension of approximately 0.318 mm (0.0125 inches) and anincluded angle about of 25 degrees. Relative measurements anddimensional sizing, are included merely to demonstrate utility of theinstant teachings, and are not intended to limit them.

[0042] In use, the material removal tip 30 is inserted into a bodyvessel or other cavity using the aforementioned guidewire 28 andconventional catheter introduction techniques not described furtherherein. The distal tip 30 is manipulated into close proximity with thetarget blockage or material deposit, the drive shaft 22 rotated, and thevacuum source 20 actuated. As the distal tip 30 is advanced toward thematerial to be removed, the suction created at the mouth 82 tends topull material into contact with the rotatable member 34 and screw thread58. The combination of suction and “Archimedes Screw” action of thescrew thread 58 draws material into the distal housing section 36, andultimately into contact with the rotating flanges 66. As the material isdrawn through the distal housing section 36, the screw thread 58performs a coarse chopping, reducing the largest material agglomerationsin size. Subsequently, the rotating flanges 66 more finely chop thematerial to reduce clogging of the tubular passageway between the driveshaft 22 and first the -proximal lumen 44 and then the inner surface ofthe elongated tube 12.

[0043] It has been found that without a shearing member, such asprovided by the distal and proximal members 100, 102, material tends tobuild up on the axially-facing surfaces of the flanges 66. Eventually,buildup of material occludes the circumferential spaces between theflanges 66, greatly diminishing the capacity of material removal, and insome instances irreversibly clogging the device. Consequently, thepresent invention provides one or more shearing members to cut orotherwise knock material from the axially facing surfaces of therotating flanges 66. Because of the relative movement between theflanges 66 and shearing members 100, 102, the discontinuouscircumferential projection of the shearing members, and the close axialspacing between these relatively moving surfaces, material iseffectively sheared from the axially facing surfaces of the flanges 66.Any material sheared from the flanges 66 is then exhausted in a proximaldirection through the annular passageway 24 within the elongated tube12. The flanges 66 are thus maintained clear of material, and theircorners thus remain unobstructed and effective in finely chopping thematerial that reaches them.

[0044] With reference to FIGS. 3 and 4, the proximal face 104 of thedistal shearing member 100 and the distal face 106 of the proximalshearing member 102 are preferably oriented normal to the axis ofrotation 37 of the member 34. In addition, the transition surfaces 114,124 are preferably axially oriented. As seen in FIGS. 2c and 2 d,therefore, the cross-sections (taken circumferentially) of the shearingmembers 100, 102 are rectangular, and shearing edges 116, 126 aredefined by perpendicular corners that face the leading edges of theoncoming flanges 66. The leading edges of each of the flanges 66 arelikewise defined by perpendicular corners 68 so that the passage of theflanges 66 past the shearing members 100, 102 creates a scissor-likeaction, serving not only to clear material from the axial surfaces ofthe flanges 66 but also to sever fibrous matter present in any materialcaught therebetween. Alternatively, one or both of the cooperating edgeson the flanges 66 and shearing members 100, 102 may be sharpened toknife edges to further facilitate the severing action, although theremay be a limit to such sharpening dictated by strength considerations.FIG. 2c shows one flange 66 having material adhered thereto andapproaching the proximal shearing member 102, while FIG. 2d showsanother flange 66 having just passed the distal shearing member 100 andbeen cleared of material.

[0045] To further facilitate the two functions of the shearing members100, 102 (i.e., clearing material from the axial surfaces of the flanges66 and also severing fibrous matter), the transition surfaces 114, 124each have a radial portion that gradually transitions to blend into thebase lumen wall, as seen in FIGS. 3b and 4 b. That is, the transitionsurface 114 gradually curves into tangency with the wall of the distallumen 42, and the transition surface 124 gradually curves into tangencywith the wall of the proximal lumen 44. The curvilinear transitionsurfaces 114, 124 thus provide a radial shear component between therespective shearing edges 116, 126 and leading edges 68 of the rotatingflanges 66. It will be clear, therefore, that the shearing action isscissor-like (as opposed to unidirectional shear) as the oncomingleading edge 68 of each flange 66 first reaches the radially outermostportion of each shearing edge 116 or 126, and then gradually reaches therest of the shearing edge. This is preferred over a situation where theflange leading edge 68 reaches the entire shearing edge at once, whichwould be the case if the surfaces 114, 124 were entirely radiallydisposed. Of course, the latter arrangement is not precluded while stillobtaining most of the benefits of the present invention.

[0046] As mentioned above, various other configurations of the materialremoval tip 30 are contemplated. For example, FIGS. 5-6 illustrate amaterial removal tip 150 having a one-piece housing 152 and a singleshearing member 154. As before, the housing 152 includes a distalsection 160, a proximal section 162, a distal lumen 164, a proximallumen 166, and an intermediate groove 168. Likewise, the rotating member170, identical to the member 34 previously described, includes outwardlyprojecting flanges 172 that are axially restrained within the groove168. The elongated tube and drive shaft are not shown in FIG. 5a forclarity.

[0047] As seen best in FIGS. 6a and 6 b, the shearing member 154 islocated just proximal to the groove 168, and thus corresponds to theproximal shearing member 102 described for the first embodiment. Thereis no distal shearing member in this embodiment. It all other aspects,the shearing member 154 is identical to the proximal shearing member 102described above, and includes an arcuate inner face 174 spanning anincluded angle 176, transition surfaces 178, and a distal face 180coincident with the proximal boundary of the groove 168. The distal face180 is thus axially adjacent the rotating flanges 172 and serves toknock material from the proximal faces of the flanges.

[0048] Although only one shearing member is shown located eitherdistally or proximally with respect to the groove, those skilled in theart will recognize that two or more shearing members on either side canalso be provided. It has been found that a single shearing member issufficient to knock material from the axially facing surfaces of theflanges, and is preferred because it minimizes the obstruction to flowof material from the distal to the proximal sections of the housing.Likewise, as mentioned above, a shearing member provided of only oneside of the rotating flanges is believed to significantly improveperformance of the device. Thus, as seen in FIGS. 5-6, a single shearingmember 154 is provided proximal to the rotating flanges 172, and anotheralternative not illustrated is a single shearing member located distallywith respect to the flanges.

[0049] A still further embodiment of the present invention is seen inFIGS. 7a and 7 b. In these views, an alternative one-piece housing 200is shown for use with a rotating member, such as the members 34 or 170described previously. Again, the housing 200 includes a distal section202, a proximal section 204, a distal lumen 206, a proximal lumen 208,and an intermediate groove 210. A distal shearing member 220 and aproximal shearing member 222 are located on opposite sides and adjacentto the groove 210. The shearing members 220 and 222 are alignedcircumferentially, as seen in the end view of FIG. 7b.

[0050] The choice of using a one- or two-piece housing depends upon themanufacturing choices available. A one-piece housing is preferred iftooling for forming the shearing members 220, 222 on the inner surfacethereof is really available. On the other hand, forming the innershearing members on the mating ends of each section of a two-piecehousing is somewhat easier, and the two sections can then be joined andwelded or otherwise fastened together.

[0051] A number of different materials are suitable for the materialremoval device, including stainless-steel, titanium, acrylic or othersuitable biocompatible and rigid materials. The selection of materialmay be dictated by the particular manufacturing process used. In apreferred embodiment, the material removal device housing is formed intwo sections of stainless-steel and includes a single shearing member oneach side of the rotating flanges. The two sections are preferably laserwelded together.

[0052] Another embodiment is shown in FIG. 8A and FIG. 8B, wherein therotatable member of the invention includes a grinder rotor 300 forgrinding material between abrasive surface 320 on the grinder rotor andabrasive surface 310 in the housing of the device. This embodiment mayfurther include at least one cutting flute 330 to aid the grinding. Inthe embodiment shown in FIG. 8A and FIG. 8B, grinding of the materialtakes place prior to contact of the material with the shearing member.Abrasive surfaces 310 and 320 may be fabricated from one or moreabrasive materials such as ceramics, diamond, quartz, silicon carbide,aluminum oxide, boron carbide, boron nitride, tungsten carbide andtitanium nitride. Alternatively, abrasive surfaces 310 and 320 can betitanium or stainless steel surfaces with a ridged, file-like surface.

[0053] Stated briefly, the various embodiments of the invention includea method of removing material from a body lumen in a patient in need ofsuch removal, comprising advancing a catheter-mounted device having adistal material removal tip including a hollow housing and a memberrotatable therewithin, rotating the rotatable member, drawing thematerial into the housing, shearing the material in the housing betweenrelatively rotating shearing members to reduce the clogging propensityof the material, removing the sheared material from within the housingas the material removal tip is advanced through the vessel.

[0054] The method may further include first coarsely chopping thematerial in the housing, and then finely chopping the material in thehousing during the step of shearing.

[0055] In another embodiment of the invention, the method utilizes arotatable member that includes a screw thread. Here, the step ofcoarsely chopping the material in the housing is accomplished by contactbetween the screw thread and the material. In another embodiment of themethod, the step of shearing includes cutting material in a scissor-likemanner between opposed shearing edges provided on the relativelyrotating shearing members. Here, the opposed shearing edges defineshearing planes for simultaneous coarse, medium and fine shearing,wherein the shearing planes comprise a range of dimensions up to about0.05 mm (about 0.002 inches).

[0056] The method may involve a catheter-mounted device having a distalmaterial removal tip that has a total preselected diameter effective foruse in a preselected body lumen, which may be a blood vessel, a lumenfor the passage of bile, a lumen for the passage of urine, a lymphvessel, a gastrointestinal lumen, and the like.

[0057] Still another embodiment involves a method of removing materialfrom and treating a body lumen with a medically useful agent in apatient in need of such removal and treatment, comprising advancing acatheter-mounted device having a distal material removal tip including ahollow housing and a member rotatable therewithin, the device furthercomprising a lumen, wherein the lumen is adapted to contain a medicallyuseful agent for release at a predetermined time; rotating the rotatablemember, drawing material into the housing, shearing the material in thehousing between relatively rotating shearing members to reduce theclogging propensity of the material, removing the sheared material fromwithin the housing as the material removal tip is advanced through thevessel; and, releasing the medically useful agent at the predeterminedtime. The release may be accomplished by pumping means, such as gaspressure, mechanical pressure, liquid pressure, and the like. Themedically useful agent may be an x-ray contrast agent, a thrombolyticagent, a viral vector, an enzyme such as a proteolytic enzyme, and thelike.

[0058] In another embodiment of the method, portions of the shearingmembers are coated or fabricated using ceramics, diamond, quartz,silicon carbide, aluminum oxide, boron carbide, boron nitride, tungstencarbide, titanium nitride and the like, whereas the rotatable member andtubular housing are constructed using stainless steel, titanium, acrylicplastic and the like biocompatible materials.

[0059] In another embodiment, the invention teaches a method of removingmaterial from a body lumen in a patient in need of such removal,comprising advancing a catheter-mounted device having a distal materialremoval tip including a hollow housing and a member rotatabletherewithin, wherein the rotatable member includes grinding means forgrinding the material, rotating the rotatable member, grinding thematerial into ground material, drawing the ground material into thehousing, shearing the material in the housing between relativelyrotating shearing members to reduce the clogging propensity of thematerial, removing the sheared material from within the housing as thematerial removal tip is advanced through the vessel. The grinding meansmay be fabricated from such abrasive materials as ceramics, diamond,quartz, silicon carbide, aluminum oxide, boron carbide, boron nitride,tungsten carbide, titanium nitride, and the like, including interactivemedia.

[0060] In another embodiment, the invention provides an article ofmanufacture, comprising packaging material and instructional materialfor the use of the method. The article of manufacture may furtherinclude percutaneous material removal devices, guidewires, introducers,containers, catheters, angioplasty balloons, stents, medicinal agents,medical syringes, and the like. The instructional material may includeprinted materials, GD disks, magnetic data storage disks, videotapes,and the like.

[0061] The present invention may be embodied in other specific formswithout departing from its spirit or essential characteristics. Thedescribed embodiments are to be considered in all respects only asillustrative and not restrictive. The scope of the invention is,therefore, indicated by the appended claims rather than by the foregoingdescription. All changes that come within the meaning and range ofequivalency of the claims are to be embraced within their scope, as ifthe same were literally set forth herein.

What is claimed is:
 1. A method of removing material from a preselected body lumen in a patient in need of such removal, comprising: advancing through said body lumen a catheter-mounted device having a distal material removal tip including a hollow housing and a member rotatable therewithin; rotating the rotatable member; drawing said material into said housing; shearing said material in said housing between relatively rotating shearing members to reduce the clogging propensity of said material; and removing said sheared material from within said housing as said material removal tip is advanced through said body lumen.
 2. The method of claim 1, further including: first coarsely chopping said material in said housing; then, finely chopping said material in said housing during said step of shearing.
 3. The method of claim 1, wherein said rotatable member includes a screw thread and said step of coarsely chopping said material in said housing is accomplished by contact between said screw thread and said material.
 4. The method of claim 1, wherein the step of shearing includes cutting material in a scissor-like manner between opposed shearing edges provided on said relatively rotating shearing members.
 5. The method of claim 4, wherein at least about a plurality of said opposed shearing edges define shearing planes for simultaneous coarse, medium and fine cutting.
 6. The method of claim 5, wherein said opposed shearing edges define said shearing planes comprising a range of dimensions up to about 0.05 mm (about 0.002 inches) for simultaneous coarse, medium and fine shearing.
 7. The method of claim 1 wherein said catheter-mounted device having a distal material removal tip has a total preselected diameter effective for use in said preselected body lumen.
 8. The method of claim 7 wherein said preselected body lumen is selected from the group consisting of blood vessels, lymph vessels, lumens for the passage of bile, lumens for the passage of urine, and gastrointestinal lumens.
 9. A method of removing material from and treating a preselected body lumen with a medically useful agent in a patient in need of such removal and treatment, comprising: advancing through said body lumen a catheter-mounted device having a distal material removal tip including a hollow housing and a member rotatable therewithin; said device further comprising a device lumen, wherein said device lumen is adapted to contain a medically useful agent for release at a predetermined time; rotating said rotatable member; drawing material into said housing; shearing said material in said housing between relatively rotating shearing members to reduce the clogging propensity of the material; removing the sheared material from within said housing as said material removal tip is advanced through said preselected body lumen; and, releasing said medically useful agent into said preselected body lumen from said device lumen at said predetermined time.
 10. The method of claim 9, wherein said release is accomplished by pumping means.
 11. The method of claim 10, wherein said pumping means is selected from the group consisting of gas pressure, mechanical pressure, and liquid pressure.
 12. The method of claim 9, wherein said medically useful agent is an x-ray contrast agent.
 13. The method of claim 9, wherein said medically useful agent is a thrombolytic agent.
 14. The method of claim 9, wherein said medically useful agent is a viral vector agent.
 15. The method of claim 9, wherein said medically useful agent is an enzyme.
 16. The method of claim 9, wherein said enzyme is a proteolytic enzyme.
 17. The method of claim 1, wherein portions of said shearing members are coated with at least one material selected from the group consisting of ceramics, diamond, quartz, silicon carbide, aluminum oxide, boron carbide, boron nitride, tungsten carbide and titanium nitride.
 18. The method of claim 1, wherein portions of said shearing members are fabricated from at least one material selected from the group consisting of ceramics, diamond, quartz, silicon carbide, aluminum oxide, boron carbide, boron nitride, tungsten carbide and titanium nitride.
 19. The method of claim 1, wherein said rotatable member and said generally tubular housing are constructed substantially of at least one material selected from the group consisting of stainless steel, titanium, and acrylic plastic.
 20. A method of removing material from a preselected body lumen in a patient in need of such removal, comprising: advancing through said preselected body lumen a catheter-mounted device having a distal material removal tip including a hollow housing and a member rotatable therewithin, wherein said rotatable member includes grinding means for grinding said material prior to said contact of said material with said shearing member, wherein said grinding means include at least one abrasive surface fabricated from at least one abrasive material selected from the group consisting of ceramics, diamond, quartz, silicon carbide, aluminum oxide, boron carbide, boron nitride, tungsten carbide, titanium nitride, titanium surfaces with a file-like surface, and stainless steel surfaces with a file-like surface; rotating said rotatable member; grinding said material into ground material; drawing said ground material into said housing; shearing said material in said housing between relatively rotating shearing members to reduce the clogging propensity of said material; and removing said sheared material from within said housing as said material removal tip is advanced through said preselected body lumen.
 21. The method of claim 20, wherein said rotatable member includes a grinder rotor having at least a first said abrasive surface, and said housing includes at least a second said abrasive surface.
 22. An article of manufacture, comprising packaging material and instructional material for the use of the method of claim
 1. 23. The article of manufacture of claim 22, further including at least one item selected from the group consisting of percutaneous material removal devices, guidewires, introducers, containers, catheters, angioplasty balloons, stents, medicinal agents, and medical syringes.
 24. The article of manufacture of claim 22, wherein said instructional material is at least one device selected from the group consisting of printed materials, CD disks, magnetic data storage disks, and videotapes. 